1. Field of Invention
The present invention relates to a lighter, and more particularly to a safety disposable lighter, which includes a heightened shielding frame for protecting a flame of the lighter from inference of wind and resisting undesired use of the lighter by children.
2. Description of Related Arts
Nowadays, U.S. government and U.S. Consumer Product Safety Commission demand a safety device in every cigarette lighter including the disposable lighter to prevent unwanted ignition accidentally or by a child. As it is known that the disposable lighter is common and relatively cheap, it is impossible to incorporate with expensive and complex safety device that highly increases the cost of the disposable lighter. In order to minimize the manufacturing cost of the disposable lighter employed with safety device, one of the most common safety disposable lighter is the driving wheel type disposable safety lighter. This type of disposable lighter comprises a pair of driving wheels for driving the striker wheel to rotate in order to generate sparks, wherein the driving wheels normally run idle when the driving wheels are physically disengaged with the striker wheel.
For example, U.S. Pat. No. 5,547,370, owned by Hwang, discloses a wheel axle mounted between two upright supports at the top of a butane wheel, two driving wheels mounted around the wheel axle and disposed in contact with a spring-supported flint below and turned by the driving wheels through the wheel axle to strike the spring-supported flint in producing sparks. The wheel axle is made of polygonal cross section, having two round rods at two opposite ends loosely inserted into a respective axle hole on each upright support so as to ensure a better connection between the striker wheel and the wheel axle.
Another example is U.S. Pat. No. 5,997,281, owned by Lei discloses two side thumb-wheel each having a circular shallow indentation are respectively mounted on two sides of a friction thumb-wheel, wherein each circular shallow indentation has an inner diameter slightly larger that an outside diameter of the friction thumb-wheel such that the friction thumb-wheel can be inserted into the circular shallow indentation. In such arrangement, when a pressing force is applied on the two side thumb-wheels, the side thumb-wheels will engage with the friction thumb-wheel, which in turn bears against a flint to create a spark.
However, most of the driving wheel type disposable safety lighters, including the above two patents, still have the following drawbacks.
Since the dimension of the driving wheels (side thumb-wheels) are not produced precisely for minimizing the manufacturing cost of the disposable lighter, there is always a clearance between the driving wheel and the striker wheel. The clearance is supposed to provide a gap that the driving wheels can rotate loosely around the axle in such a manner the driving wheels are run idle around the axle. However, the clearance also provides a gap that the driving wheels can axially loose such that the driving wheels may not perfectly engage with the striker wheel in order to provide an optimum mutual friction therebetween for ignition. Furthermore, in order to ignite the lighter, a downward force must be applied on the driving wheels for engaging the striker wheel. In fact, the driving wheels are always engaged with the striker wheel by gravity which acts as the downward force. In other words, the lighter, which claims as a safety lighter, may normally in a ready-to-ignite position.
Moreover, the manufacturing process of the conventional lighter is rather expensive and complicated. An extra process is needed to from an indentation on a side of the driving wheel. The circumferential surface of the indentation is serrated to provide frictional contact with the striker wheel, which is loosely fitted into the indentations of the driving wheels. An axle coaxially passing through the driving wheels and striker wheel is needed for rotatably mounting them onto a frame. In other words, the safety feature of the conventional lighters is achieved on the expenses of manufacturing costs and difficulties.
In addition to safety features, windproof is an area where much effort has been dedicated for a more effective lighter. A flame is composed of a main flame, the inner part, and a visible flame, the outer part. The main flame is a lot hotter than the viable flame, and is used for lighting a cigarette. A conventional lighter generally includes a shielding frame for protecting the main flame from interference by wind, and maintain the flame not extinguished. One of the considerations for designing the shielding frame is that its height must not block the operation of the driving wheels and striker wheel. As commonly observed, the shielding frame of conventional disposable light has a moderate height that exposes about one half of the driving wheel for purposes of effective operation. However, this height may not properly protect the main flame from interference of wind. Thus, the traditional disposable lighter is often troubled by undesired extinguishment of flame.